1. Field of the Invention
The present invention relates to a terminal contact and clamp assembly, and more particularly to a terminal contact and clamp assembly for a cable terminal block and a method for processing the terminal contact and clamp assembly. The terminal contact and clamp assembly securely and tightly bites and holds an exposed wire core at one end of a cable.
2. Description of Related Art
Cable terminal blocks are used generally in electronic devices for holding ends of cables so that the electronic devices are capable of transmitting power or electronic signals to other devices through the cables.
With reference to FIGS. 7 and 8, a conventional cable terminal block comprises a casing (90) and a contact and clamp assembly.
The casing (90) has a cavity (91) and a mounting hole (92). The cavity (91) is defined in the casing (90) for holding one end of a cable (99) having a wire core exposed at the end. The mounting hole (92) is defined in the casing (90) and communicates with the cavity (91).
The contact and clamp assembly is mounted in the cavity (91) and has a cage clamp (95), an inner contact (96), an outer contact (97) and a bolt (98). The cage clamp (95) is conductive, is mounted in the cavity (91) and has an inner bottom surface, a front open end, a rear open end, a threaded hole (953), a through hole and multiple bottom teeth (951). The threaded hole (953) is defined through the top of the cage clamp (95). The through hole is defined laterally through the cage clamp (95) and communicates with the threaded hole (953) and the front and rear open ends. The bottom teeth (951) are formed on the inner bottom surface with a punching process.
The inner contact (96) is conductive, is mounted through the rear open end of the cage clamp (95), cooperates with the cage clamp (95) to clamp and hold the end of the cable (99) and has an inner top surface and multiple top teeth (961). The top teeth (961) are formed on the inner top surface with a punching process and correspond to and cooperate with the bottom teeth (951) to clamp and hold exposed wire core at the end of the cable (99).
The outer contact (97) is conductive, is mounted through the rear open end of the cage clamp (95) and is stacked on the inner contact (96).
The bolt (98) is mounted through the mounting hole (92) and the threaded hole (953) and presses against the outer contact (97) and the inner contact (96) to clamp the exposed wire core at the end of the cable (99) with the cage clamp (95).
However, the bottom and top teeth (951, 961) formed with punching processes are not sharp so that the wire core of the cable (99) cannot be bitten tightly by the bottom and top teeth (951, 961) and would therefore slip out of the contact and clamp assembly.
With reference to FIGS. 9A to 9C, a conventional method for pressing the contact and clamp assembly comprises aligning a punch die (85) with a workpiece (80) as shown in FIG. 9A and punching a surface of the workpiece (80) with the punch die (85) to finish a product, as shown in FIGS. 9B and 9C. The punch die (85) has multiple punching teeth (851) and multiple V-shaped grooves located respectively between adjacent punching teeth (851). The workpiece (80) is made of bronze or red copper. The punching teeth (851) on the punch die (85) punches in the surface to form multiple indents and multiple teeth (951, 961) arranged alternately with the indents. The pressed metal workpiece is processed later to form the cage clamp (95) or inner contact (96) and the teeth (951, 961).
However, the conventional method has following disadvantages.
1. When the punching teeth (851) punches the workpiece (80), material of the workpiece (80) cannot entirely fill the V-shaped grooves so that the teeth (951, 961) formed from the material filling into the V-shaped grooves are round instead of being sharp. Accordingly, the round teeth (951, 961) on the cage clamp (95) or inner contact (96) formed from the workpiece (80) barely bite the end cable (95) and easily allow the cable to slip out of the contact and clamp assembly, especially when the cable has a multi-core.
2. The workpiece (80) made of bronze or red copper with a low hardness as compared with iron or steel so that the teeth (951, 961) are round.
3. The wire core of the cable (99) may be a single core or a multi-core having a bundle of core elements. When the wire core is a single core, the contact and clamp assembly barely bites and holds the single core. However, when the wire core is a multi-core, the contact and clamp assembly hardly bites and holds the multi-core and the cable easily slip out of the contact and clamp assembly.
To overcome the shortcomings, the present invention provides a terminal contact and clamp assembly for a cable terminal block and a method for processing a terminal contact and clamp assembly to mitigate or obviate the aforementioned problems.